An infiltration intake system for a revetment wall including a filter storage portion is known in general, as disclosed in Japanese Patent Laying-Open No. 2013-75268, for example.
Japanese Patent Laying-Open No. 2013-75268 discloses an infiltration intake unit including a sand filtration layer, a box-type housing, storing the sand filtration layer, set undersea on a seabed surface and an intake pipe for supplying water passing through the sand filtration layer to a seawater desalination plant. The intake pipe of the infiltration intake unit is formed to extend ashore from the undersea housing.